The present invention relates to a water spray gun having an improved sprinkler head structure for use on a garden hose. The sprinkler head has a head body and a sprinkling cap and a bottom plate that are joined together by way of ultrasonic welding art. The sprinkling cap is rotatably mounted onto the head body. The head body has a water outlet and a spring receiving hole in which a spring biased locking pin is housed. The locking pin can be selectively engaged with one of a number of retaining cavities defined on one side of the bottom plate. The sprinkling cap has a peripheral ring area having a plurality of sprinkling pores and a number of water discharge holes of various geometric shapes. Each water discharge hole of the sprinkling cap has a tubular extension and the tubular extensions are bridged by vertical wall sections and an S-shaped wall section to define a closed area. The bottom plate has a plurality of circular holes ending with protruded flanges that defines a closed area in correspondence to that of the sprinkling cap. On the bottom plate and inside and outside of the closed area are disposed a small rhombic opening in communication with a circular hole of the sprinkling cap and a large rhombic opening in communication with the ring area respectively that can be registered with the water outlet of the head body separately of simultaneously so that water can be discharged via the discharge hole or the ring area of the sprinkling cap separately or together.
In general, conventional water spray guns of various kinds for use on a garden hose have a sprinkling cap and a bottom plate bound together by the ultrasonic welding and an head body. The prior art sprinkling cap rotatably mounted onto the head body has a number of differently shaped discharge holes and water flowing through a water outlet of the head body can only be discharged via one of the discharge holes without multiple variations.